Air cleaner and humidifier

ABSTRACT

The present invention relates generally to apparatus for the cleansing and humidification of particulate laden air, and comprises means for receiving particulate laden air and generating a vortical flow pattern, apparatus for injecting water vapor into said flow pattern whereby the water vapor impregnates the particulate causing the same to be centrifuged from the air flow, means for decelerating and interrupting the vortical flow to thereby remove additional particulate and excess moisture therefrom, and a collector for receiving excess moisture and particulate removed from the air.

BACKGROUND OF THE INVENTION

Air quality is a subject of major concern in a wide variety ofindustries. The control of particulate matter picked up and carried byair in enclosed working areas is of particular concern to the employeras well as to the employees working in a particulate laden environment.While there are a wide variety of pollutants which are indigenous tovarious industries, the present invention concerns itself primarily withwhat may be termed broadly as dust, but which is found to be prevalentin many agricultural processes such as cotton ginning, milling and thelike. Apparatus for scrubbing and treating gasses has become virtuallyan industry unto itself. Devices such as huge air bags which filterexhaust air have been developed at high cost, but their size and cost ofoperation relative to the amount of exhaust gas they are capable ofhandling has made them prohibitive in some industries. Along with thedust problem is the problem of humidity which in many industries must bemaintained at a pre-determined level not only for employee comfort, butto minimize static electricity and other problems attendant low-humidityair.

It has been recognized as far back as 1952 in the Johnstone et al. U.S.Pat. No. 2,604,185, that by injection of a fluid such as water into anair stream, a certain amount of particulate will absorb the moisture andthe added weight will result in its being dispersed from the air stream.Others, such as Deane, in his U.S. Pat. No. 3,802,162 have recognizedthe value of centrifuging moisture laden particulate out of an airstream moving through the system. Apparatus such as that of Dean,however, use large volumes of water, in the neighborhood of 30 gallonsper minute, and involve highly complex multi-stage, high energy demandsystems which complicate and add to the expense of the system withoutincreasing its efficiency.

The apparatus of the present invention makes use of many of thepreviously recognized physical principals in the development of a simpleyet highly effective scrubbing device having a single scrubbing chamber,including a longitudinal opening for removal of scrubbed particulatefrom the chamber and further employing a means of interrupting flow fromthe chamber to bring about a final or second stage removal ofparticulate and excess moisture without any type of filtering device. Asa result, through the use of controlled water injection and a uniquemeans of generating moisture particles, the air passing through thechamber, which is relatively small in size, is effectively cleansed andhumidified to provide optimum atmospheric and environmentally acceptabledischarge air.

BRIEF DESCRIPTION OF THE DRAWING

Having thus briefly summarized the invention, reference may not be hadto the drawing wherein,

FIG. 1 is a side elevation of a device constructed in accordance withthe present invention, sectioned to illustrate the operativerelationship of the various parts;

FIG. 2 is a partial sectional view of FIG. 1 taken along line 2--2; and

FIG. 3 is a top plan view of the device of FIG. 1.

FIG. 4 is a schematic depiction of the combined air movement and waterinjection system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the drawings, and in particular to FIG. 1 thereof,there is shown an apparatus indicated generally at 10 constructed inaccordance with the present invention and comprising a housing 12through which particulate laden air is forced for the purposes ofscrubbing and humidifying the same. Within the housing there is provideda tubular member 15 which, as may be seen in FIG. 1, extends the lengthof the housing 10 and is essentially horizontal in attitude.

Air is drawn into the tubular member 15 through an inlet 17 by means ofa fan indicated generally at 19. The fan is so constructed as to drivethe air axially in the direction A through the tube while at the sametime generating vortical flow as indicated by the arrows B.

As may be seen in FIGS. 1 and 4, a drive shaft 22 is a part of a motor24, in the present case, hydraulically driven, which drives the impellerblades 26. The shaft 22 is in reality a tube which is fed by a waterline 30 through which water flows into a dispersion device 33 attachedat the end of the shaft and rotatable therewithin. The water flowpassing through the rotating device is broken up into millions of minutedroplets of relatively uniform size by rotation of the fan, resulting ina "fogging" of air being moved by the blades 26. The water droplets tendto impregnate the drier particulate matter entrapped in the vortical airflow and as a consequence, the moistened particulate becomes heavy. Thevortical flow tends to centrifuge the heavier particles towards theinner wall of the chamber 15 where they tend to stick and form a slurryof moist particulate matter.

The degree of saturation may, in accordance with the present invention,be controlled by the speed of the fan and the amount of water injected.It has been found that water droplet size may be controlled in thisfashion and for that purpose, a flow regulator 35, of known constructionis provided.

The slurrey will form on the inner wall of the chamber throughout itslength and as build-up becomes significant, air movement and gravitywill cause the slurrey to move down the walls as shown by the arrow C inFIG. 2. In order to permit the slurrey to be scavenged from the chamber,a slot or opening 38 is formed longitudinally along the lower extremityof the chamber 15. The opening 38 is defined by a sharply verticalsurface 40 which encourages discharge of heavier elements of the slurreyfrom the chamber. Additionally, the vertical surface 40 serves thepurpose of providing a knife-like edge resulting in a sheeting effect inthat as the outer extremity of the vortical flow, which contains amajority of the heavier moisture laden particulate moves past the slot,the combination of centrifugal and gravitational forces cause theparticulate to impinge upon the vertical surface 40 of the slot therebysheering or cutting away a portion of the particulate matter anddischarging it downwardly.

In order that the slurrey might be collected and eventually removed fromthe housing in order to permit continuous operation, a trough 43 isdisposed beneath the tubular cylinder 15 where the particulate slurreyis collected and periodically removed by a pumping system 45 of knownconstruction.

While the vortical flow in the chamber 15 results in major scrubbing ofthe inlet air, some of the lighter particles still entrapped in the airflowing peripherally about the inner wall of the tubular cylinder 15are, in accordance with the invention, discharged upwardly through adischarge funnel 47. When the vortical flow reaches the end of thechamber 49 it is, of course, stopped and an air cushion developes whichresults in air being forced upwardly through a vertically disposedfunnel 47 in the direction of the arrow D. The discharge funnel 47 isshaped to permit the volume of discharged air to expand rapidly with theresultant decrease in its velocity and attendant decrease in its abilityto support wetted particulate matter. This air tends to retain some ofthe swirling motion developed in the chamber 15 and it has been foundthat disrupting the motion of the air and causing it to decelerate, asubstantial portion of the remaining moistened particulate stillentrapped in the air flow, will become separated from it. Accordingly,and in keeping with this aspect of the invention, a turbulator device 52is provided which deflects the air generally seen by arrows E, therebydisrupting and turbulating the flow of the air. At the same time, theair which had been confined in the chamber 15 and had thus developed acertain amount of pressure, as it moved longitudinally towards thefunnel 47 is permitted to expand into the plenum area 54 which is formedby the housing disposed about the tubular cylinder 15. As a consequence,much of the remaining moistened particulate in the air, along withexcess moisture in the form of water droplets, tends to fall out of theair, about the tube 15 and into the collector trough 53. The scrubbedand humidified air is then discharged through opening 57 and may bepumped, by any known means, back into the environment from which itcame, or it may be discharged to exhaust if that is desirable.

Accordingly, a highly efficient, readily controlled scrubbing apparatusis provided which includes a humidifying feature to thereby provideenvironmentally acceptable atmosphere automatically. For example, aseven and one-half horsepower motor in the environment of the presentinvention can move as much as 8,000 cubic feet of air per minute, andeffectively remove dust and humidify with, in many cases, as little asone-quarter gallon of water per minute.

Having thus described the preferred embodiment of the invention, what isclaimed is:
 1. Apparatus for cleaning particulate laden air andhumidifying the same comprising a housing, means defining a tubularchamber extending longitudinally of said housing, a fan disposed at oneend of the chamber, motor means, including a rotating shaft for drivingsaid fan, said fan mounted on said shaft and disposed at one end of saidchamber for pulling particulate laden air into said chamber, and formoving said air in a vortical flow pattern through said chamber, meansdisposed on such shaft forward of said fan and at the center of thevortex generated thereby for injecting water vapor into said vorticalflow for wetting the particulate in said air flow thereby causing theparticulate to be forced outwardly and against the walls of the chamber,means defining a longitudinal slot in the bottom of said chamber topermit moisture laden particulate scrubbed from the air flow to begravitationally dispersed from said chamber, means defining a verticallydisposed discharge funnel near the end of the chamber remote from saidfan for permitting discharge of air from said chamber, means fordeflecting the flow of said discharged air to further decelerate thesame, thereby causing additional particulate matter and moisture to beremoved therefrom, a collector defined at the base of said housing forcollecting excess moisture and particulate, an outlet means formed insaid housing for permitting the discharge of cleansed and humidified airtherefrom.
 2. The apparatus as set forth in claim 1 wherein controlmeans is provided for adjusting the volume of water injected into saidvortical air flow stream.
 3. The apparatus of claim 1 wherein said meansdefining a slot includes a vertical surface adapted to cut heavierparticulate elements out of the air for discharge into said collector.4. The apparatus of claim 1 wherein pumping means is included forremoval of slurrey from said collector.
 5. The apparatus of claim 1wherein means defining a dispersion is attached to, and rotatable withsaid fan, said water vapor being discharged through said dispersiondevice for breaking said water vapor into particles of minute size. 6.The apparatus of claim 5 wherein said motor is hydraulic and said shaftis hollow so as to permit water to be injected through said shaft intosaid dispersion device.
 7. The apparatus of claim 5 wherein water isinjected into said shaft at the rate of no more than one-half gallon perminute per 8,000 cubic feet per minute air flow past said fan.